In situ crosslinking of polyelectrolytes

Abstract

A composition, useful for forming absorbent articles of a carboxylic polyelectrolyte, is prepared by copolymerizing a carboxylic polyelectrolyte monomer, a reactive self-crosslinking monomer and a hydrophobic monomer. The composition in the form of an emulsion or a viscous solution has an extendable shelf life and may be used to produce a superabsorbent material or a substrate impregnated with a superabsorbent material.

What is claimed: 
     
       1. A process for producing absorbent materials comprising: (a) a carboxylic polyelectrolyte monomer;   (b) a reactive self crosslinking monomer having the formula: ##STR4## wherein R is selected from the groups consisting of H or CH 3 , n is selected from the group consisting of zero or the integers 1 to 5, and X is selected to be a group capable of reacting through self condensation or with carboxylic acid by condensation or ring opening; and   (c) a hydrophobic monomer; wherein whenever X in (b) above is either N-methylol or an N-methylol alkyl ether, the composition has a pH of at least 7; copolymerizing said monomers to form a poly(electrolyte) self crosslinking copolymer dispersed in water; and drying said dispersion to produce absorbent material comprising crosslinked poly(electrolyte) copolymers.     
     
     
       2. The process of claim 1, wherein said absorbent material is incorporated into a substrate by applying said dispersion to said substrate and then drying to produce crosslinked poly(electrolyte) in situ. 
     
     
       3. The process of claim 2, wherein said substrate is a fibrous web. 
     
     
       4. The process of claim 2, wherein said substrate is a cellular polymer.